1. Field of the Invention
The present invention relates generally to an internal combustion engine and more specifically to an improved cylinder head for an internal combustion engine wherein coolant is introduced thereinto in liquid form and exhausted to a heat exchanger in a gaseous form.
2. Description of the Prior Art
European Patent Application No. 0 059 423 published on Sept. 8, 1982 discloses an arrangement wherein, as schematically shown in FIG. 1 of the drawings, liquid coolant in the coolant jacket of the engine 1, is not circulated therein and permitted to absorb heat to the point of boiling. The gaseous coolant is adiabatically compressed in a compressor 3 so as to raise the temperature and pressure thereof and introduced into a heat exchanger 4. After condensing, the coolant is temporarily stored in a reservoir 5 and recycled back into the coolant jacket via flow control valve 6.
However, this arrangement has suffered from a drawback in that the coolant in the coolant jacket 7 (see FIG. 2) upon boiling, occasionally tends to form large gas bubbles which displaces the coolant out of the cylinder head 8 in the form of a boiling froth or foam which is subsequently inducted into the compressor 3. This induces a sudden removal of coolant from the coolant jacket 7 and tends to permit localized dry spots to form therein. These spots, due to the temporary lack of coolant become excessively heated and further promote the "dry-out" phenomenon. This problem is particularly prevalent in zones of high heat flux such as in the vicinity of the exhaust valve seat and tends to induce engine knocking and/or thermal damage.